NAME

atan, atanf — arc tangent function of one variable

LIBRARY

Math Library (libm, -lm)

SYNOPSIS

#include <math.h>

double
atan(double x);

float
atanf(float x);

DESCRIPTION

The atan() and atanf() functions compute the principal value of the arc tangent of x in the range [-pi/2, +pi/2].

SEE ALSO

acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3)

STANDARDS

The atan() functions conforms to ANSI X3.159-1989 (“ANSI C89”).